The 20th element on the Periodic Table, Calcium is one element without which the human skeleton structure cannot exist. Now, do you understand its importance? Well, since you know the importance of Calcium, we will take you through 65 fascinating Calcium facts covering its discovery, characteristics, uses, and more. So, grab your coffee, pull up your sleeves, and join us on this incredible journey of learning – a journey that never ends!

Let us begin!

Facts about Calcium – Some Basic Information at a Glance

Element Name

Calcium

Element Symbol

Ca

Element Family

Alkali Earth Metal

Color

Silvery-gray

State

Solid

Atomic Weight

40.078

Melting Point

842˚C or 1115 K

Boiling Point

1484˚C or 1771 K

Density at 20˚C

1.55 g/cm3

Number of Electrons

20

Number of Protons

20

Number of Neutrons (as found in the most abundant isotope)

20

Electronic Configuration

1s2 2s2 2p6 3s2 3p6 4s2

Known Isotopes

25 know isotopes so far

Element Structure

Cubic close-packed or ccp

Atomic Radius

180 pm

Hardness

1.75 mohs

Facts about Calcium – Isotopes of Calcium

Isotope Name

Type and Abundance

Half-Life (HL)

34Ca

Radioactive

< 35 nanoseconds

35Ca

Radioactive

25.7 milliseconds

36Ca

Radioactive

102 milliseconds

37Ca

Radioactive

181.1 milliseconds

38Ca

Radioactive

440 milliseconds

39Ca

Radioactive

859.6 milliseconds

40Ca

Radioactive and 96.94% natural abundance

> 3.0×10+21 years

41Ca

Radioactive

1.02×10+5 years

42Ca

Stable and 0.647% natural abundance

Stable, and hence, no HL

43Ca

Stable and 0.135% natural abundance

Stable, and hence, no HL

44Ca

Stable and 2.09% natural abundance

Stable, and hence, no HL

45Ca

Radioactive

162.61 days

46Ca

Radioactive and 0.004% natural abundance

> 0.28×10+16 years

47Ca

Radioactive

4.536 days

48Ca

Radioactive and 0.187% natural abundance

> 5.8 x 1022 years

49Ca

Radioactive

8.718 minutes

50Ca

Radioactive

13.9 seconds

51Ca

Radioactive

10.0 seconds

52Ca

Radioactive

4.6 seconds

53Ca

Radioactive

90 milliseconds

54Ca

Radioactive

86 milliseconds

55Ca

Radioactive

22 milliseconds

56Ca

Radioactive

11 milliseconds

57Ca

Radioactive

> 620 nanoseconds

58Ca

Radioactive

> 620 nanoseconds

Now that we have all the basic information in hand, we can proceed with our facts list. Shall we? Fine! Let us start.

Calcium Facts: 1-6 | Use of Calcium by Romans

1. Like many other elements on this Earth, Calcium was already in use for several thousand years. For instance, the element was used in the form of cement.

2. One of the most well-documented applications of Calcium compound was during the Roman era. The Romans used Calx.

3. Calx was nothing but Limestone. Romans used to call Limestone as Calx.

4. The Romans used to heat the Calx to remove Carbon Dioxide from it. What was left behind was Calcium Oxide.

5. They then mixed the Calcium Oxide with water to make cement. They used the cement for building massive amphitheaters as well as aqueducts.

6. The Romans used the cement for binding stones together in those structures.

Calcium Facts: 7-11 | Discovery of Calcium in Early 19th Century

7. Yes, Calcium compounds were extensively used throughout history. The only problem was that no one knew about elemental Calcium.

8. It was only after the discovery of electricity that attempts were made to isolate Calcium.

9. The first successful isolation of Calcium took place in 1808. The person who achieved it was Sir Humphry Davy. He did this in London.

10. In June 1808, Davy gave a lecture in the Royal Society. During the lecture, Davy gave a complete account of the experiment that he used for isolating Calcium.

11. The experiment that Davy used was capable of producing only tiny amounts of Calcium. Davy failed to figure out how to produce more Calcium.

Calcium Facts: 12-20 | Some Help from Jöns Berzelius

12. Davy understood what to do to produce more Calcium only after he received a letter from Jöns Berzelius.

13. In the letter, Berzelius told Davy that along with Magnus Pontin, Berzelius managed to produce an amalgam of Mercury and Calcium.

14. Pontin and Berzelius used Calcium Oxide and decomposed the compound on a Mercury electrode using a battery. This resulted in the production of the Mercury-Calcium amalgam.

15. Berzelius, who was a brilliant chemist from Sweden, was always in contact with Davy and it was Davy who told Berzelius that one could dissolve Potassium into Mercury to produce an amalgam.

16. Berzelius used the information from Davy and extended it to produce Mercury-Calcium amalgam.

17. After hearing from Berzelius, Davy took the slaked lime and red oxide of Mercury and made a paste. Slaked lime is Calcium Hydroxide formed by slightly moistening Calcium Oxide.

18. Once he made the paste, he created a depression right in the middle of it. Davy placed precisely 3.5 grams of Mercury into the depression.

19. The Mercury was placed there to act as an electrode. Davy then used Platinum as a counter electrode.

20. He carried out the entire experiment under a liquid hydrocarbon called Naphtha. Naphtha, a Davy found out earlier, was a perfect medium to store Sodium and Potassium safely.

21. After Davy created the entire setup, he passed electricity through the slaked lime and Mercury red oxide paste.

22. The electricity did the necessary trick and created Mercury-Calcium amalgam at the Mercury electrode.

23. Once Davy received the Mercury-Calcium amalgam, he used the method of distillation to remove Mercury from the amalgam successfully. This isolated a new metal – Calcium.

24. It was Humphry Davy who gave the element the name Calcium. He derived the name from Calx – the compound that Romans used.

25. Humphry Davy later went to isolate Magnesium, Barium, and Strontium using the same method he used for separating Calcium.

Calcium Facts: 26-36 | Characteristics of Calcium

26. Calcium is a very ductile metal. This means that it can be drawn into a thin wire very easily.

27. Calcium has 20 electrons out of which the last two are the valence electrons in the s-orbital (the outermost shell). So, Calcium easily gives up the two valence electrons to get the stable configuration of Argon.

28. Since Calcium almost always gives up two electrons, it always forms dipositive ions and, in its compounds, it is almost always divalent.

29. Compared to Lead, Calcium is harder. However, you can still cut it using a knife if you put in some effort.

30. Since Calcium quickly reacts with atmospheric Oxygen, it cannot be used as a conductor for terrestrial applications. So, scientists are thinking of using it in space as a conductor.

31. In the flame test, Calcium always burns with a bright orange-red flame.

32. Calcium spontaneously reacts with water, and this reaction is faster than the reaction between Magnesium and water.

33. On the other hand, the reaction between Strontium and water is faster than the reaction between Calcium and water.

34. When Calcium is finely divided, it will burn in air spontaneously to produce nitride.

35. In the presence of moist air, Calcium will quickly form a hydration coating. It is because of this, the only way to indefinitely store Calcium at room temperature is to maintain a relative humidity of less than 30%.

Calcium Facts: 37-48 | Biological Role of Calcium

37. Calcium plays a critical role in all living organisms. In particular, it is vital for the growth of healthy bones and healthy teeth.

38. The bones in the human body contain Calcium Phosphate as the main component.

39. Did you know that nearly 1 kilogram of Calcium is present in an adult human body?

40. In plant and animal cells, Calcium plays a vital role in cellular communication. Calcium ions play the role of messengers among cells. Hence, the element plays a very essential role in multicellular organisms.

41. The human body cannot absorb Calcium directly. Though we are being said that we should drink cow’s milk to get more Calcium, the truth is entirely different. The human body cannot absorb the Calcium present in milk. Read our thorough article on Milk Myth now.

42. Did you know that to absorb Calcium, the human body needs Vitamin D? But again, Vitamin D should be in its activated form known as Calcitonin.

43. To activate Vitamin D, the body needs Magnesium, which is a cofactor in 80 percent of all cellular enzymes present in our body.

44. Did you know that Calcium is the 5th most abundant element in the human body?

45. While Calcium is the 5th most abundant element in the human body, it is ‘THE MOST ABUNDANT’ metal in the human body!

46. Of all the Calcium present in human body, 99% is stored in teeth and bones. The remain 1% does a wide range of activities in the body including assisting the movement of blood, transfer of a message between the brain and other body parts, the release of enzymes and hormones, etc.

47. Did you know that Calcium is also present in cartilages found in the human body? Cartilage is a soft connective tissue that is located in the rib cage, nose, ear, and between various joints in our body.

48. There is a specialized gland in the human body that is responsible for regulating Calcium in our body. The gland is known as the Parathyroid Gland. This gland is a part of the Endocrine System.

Calcium Facts: 49-59 | Calcium Fun Facts

49. Calcium is the 5th most abundant element (by mass) in Earth’s crust.

52. Most of the Calcium salts that we know of are readily soluble in water.

53. Not only do humans use Calcium compounds for building homes, but there are also animals as well that use Calcium compounds for building their homes. For instance, many shellfish and snails use Calcium Carbonate to build their own homes that are nothing other than their shells.

54. Calcium Bicarbonate is found dissolved in Hard Water. When Hard Water reaches caves after filtering through the ground, the water precipitates out forming stalagmites and stalactites.

55.Egyptians built their pyramids using blocks of limestone. Limestone is nothing but crystallized Calcium Carbonate.

56. During later times, the Egyptians started using lime-based mortar or Gypsum for holding the limestone blocks together.

57. In case you didn’t know, lime is nothing other than Calcium Oxide, and Gypsum is nothing other than Calcium Sulfate Dihydrate.

58. You have heard the word ‘limelight’, right? But what exactly is that? Lime, as we said earlier, is Calcium Oxide. When you burn lime in an Oxyhydrogen flame, it gives a brilliant light that is quite intense. This light is called limelight.

59. Did you know, before electricity was discovered, the limelight was used to light up the stages in all theaters? Limelight was widely used in the 1800s.

Calcium Facts: 60-65 | Uses and Availability

60. Many Calcium compounds are used for making paint, paper, lime, glass, cement, sugar, etc.

61. The compounds of Calcium are used for removing impurities of non-metallic nature from alloys.

62. Calcium has two valence electrons, and hence, it works as a reducing agent for preparing other metals like Thorium and Uranium.

63. As far as availability of Calcium is concerned, it makes up 4.1% of Earth’s crust by mass. Unfortunately, Calcium in its elemental form is not found in Nature.

64. Calcium is available in Nature in the form of various minerals such as:

Calcium Fluoride – usually known as Fluorite.

Calcium Sulfate or Gypsum.

Calcium Carbonate or Limestone.

Apatite or Calcium Chlorophosphate or Calcium Fluorophosphate.

65. The method of commercial preparation of Calcium includes the heating of lime with Aluminum. The process is carried out in the vacuum.